London Smog May Be Tough on Olympians

WEDNESDAY, July 25 -- Air pollution may aggravate breathing problems among athletes with asthma or a related condition known as exercise-induced bronchoconstriction at the 2012 Summer Olympics in London, an allergists' group warns.

"It has been well documented that elite athletes in the Olympics have an increased prevalence of [exercise-induced bronchoconstriction]," Dr. William Silvers, a member of the American Academy of Allergy, Asthma & Immunology's Sports Medicine Committee, said in an academy news release. "They may not have suspected it, since they don't have chronic asthma but rather a narrowing of the airways that comes specifically with exercise."

Also known as exercise-induced asthma, exercise-induced bronchoconstriction affects one in six Olympic athletes and about 20 percent of elite athletes.

The condition causes otherwise healthy people to experience symptoms -- such as coughing, wheezing, chest tightness and shortness of breath -- during or after exercise.

Air pollution can worsen these symptoms, the experts warned. Pollutants, including ozone, sulfur dioxide and nitric oxide, can inflame the airways of sensitive people and bring on an asthma attack.

Symptoms of the exercise-induced respiratory problems can start within 5 to 20 minutes of beginning physical activity, but more commonly, symptoms develop after physical activity has ended.

"Whether you are a professional athlete or a backyard enthusiast, understanding warning signs, staying hydrated and knowing when to use your medication can help control asthma and keep you from sitting on the sidelines," Silvers said.

Exercise-induced bronchoconstriction can be treated with prescription asthma medications, including inhaled corticosteroids to prevent symptoms from occurring and "rescue" medications, such as albuterol, which relax and open the airways. Olympic anti-doping regulations have recently changed to allow the use of some inhaled asthma medications that were previously banned, according to the release.

The summer Olympics will run from Friday, July 27 through Sunday, Aug. 12.